I was surprised to find nothing when I searched black metal in this forum, and I know there has to be some people who are into black metal and play it. So how about some tips? Aside from just listening to black metal bands and being inspired by how they play.

Chords? Tunings? Effects? Equipment? Techniques?

Add anything! I've been trying to play with a drop D tuning, and even with drop d flat (I think flat notes are referred to as half steps.) But I don't think this drop d business is working out so well, it's actually too thick when I go to use the sixth string. So feel free to add all the things you use to create your music.

I find that generally moving progressions in shorter intervals (distance from one note to the other), gives a more dissonant, evil effect. For instance, moving from A to C or whatever gives it a rather tame 'evil' sound then moving from A to let's say, E. Minor intervals are pretty good for that too, also diminished 5ths and whatnot. Also, when making those trebley, high pitched riffs like the ones Burzum would use in Jesus' Tod or Watain etc. they are just take notes from normal chords and playing them in a pattern that sounds evil. Just like the 'inverted' power chord.

I wish I had more technical knolwedge about playing guitar, ha I'm quite ignorant about it really. I was playing around last night and decided to experiment a bit more, while tremelo picking I went from the stand powerchord fingering of lets say 7-9, 9-11, 6-8 and so on, but would randomly throw in a brief note that was off that included slight stretches of 7-10 or 9-12 and it actually gave kind of a nice effect. But just playing like that sounded terrible, so it made for good accenting notes between proper ones.

When I'm going for a black-metal kind of sound I like to use strings of muted 8th notes with capo-ish chordes thrown in sliding a half-step at a time. It gives it kind of a dark, sludgy effect.
ex.
-|---------------4/3-|--------------3/4-|
-|---------------4/3-|--------------3/4-|
-|---------------4/3-|--------------3/4-|
-|---------------4/3-|--------------3/4-|
-|---------------4/3-|--------------3/4-|
-|0-0-0-0-0-0-4/3-|0-0-0-0-0-0-3/4-|